From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2A96CA9EC9 for ; Mon, 4 Nov 2019 22:06:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90C1E20650 for ; Mon, 4 Nov 2019 22:06:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572905164; bh=ZZLlPeXBR+EVEvw0FmNfaS2VKB63dks1AB/dmDQjob4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N8AGO+hMUIlQiurvw+DzeHfP0OOaKEA05+Z5+CTo5evuDUutZhuKEth35MVKL3sfP 1d3KxHS1FezMzSirQfmebii65UQ4IHSwDSszjKoImIox+Enh+PQLS8BTYXcauO/Ku3 1JUVesk2RLIa3Tyx3nIYJg05tz6zZxM5WeOZu49c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389901AbfKDWGC (ORCPT ); Mon, 4 Nov 2019 17:06:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:37662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388887AbfKDWGB (ORCPT ); Mon, 4 Nov 2019 17:06:01 -0500 Received: from localhost (6.204-14-84.ripe.coltfrance.com [84.14.204.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 750432190F; Mon, 4 Nov 2019 22:06:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572905161; bh=ZZLlPeXBR+EVEvw0FmNfaS2VKB63dks1AB/dmDQjob4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ss3kOJ/hNphNygQwxgFGL6vVlhUw+0xgmd/TdHESim840liKFzSY6A+9Oopxksw+W N7ehAqq8WzWulWxdTJUNEDwn/nF8Jb2yUSMmUeUhCwWJQ9cTWOvKKRDcdWSP4UxM0W QhfWIBB//DpgPdzJ2xoW/Iw7qTGnfaYvXpRrtUkU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andi Kleen , Jiri Olsa , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.3 011/163] perf script brstackinsn: Fix recovery from LBR/binary mismatch Date: Mon, 4 Nov 2019 22:43:21 +0100 Message-Id: <20191104212141.304255192@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191104212140.046021995@linuxfoundation.org> References: <20191104212140.046021995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andi Kleen [ Upstream commit e98df280bc2a499fd41d7f9e2d6733884de69902 ] When the LBR data and the instructions in a binary do not match the loop printing instructions could get confused and print a long stream of bogus instructions. The problem was that if the instruction decoder cannot decode an instruction it ilen wasn't initialized, so the loop going through the basic block would continue with the previous value. Harden the code to avoid such problems: - Make sure ilen is always freshly initialized and is 0 for bad instructions. - Do not overrun the code buffer while printing instructions - Print a warning message if the final jump is not on an instruction boundary. Signed-off-by: Andi Kleen Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20190927233546.11533-1-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-script.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 0140ddb8dd0bd..c14a1cdad80c0 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1054,7 +1054,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, continue; insn = 0; - for (off = 0;; off += ilen) { + for (off = 0; off < (unsigned)len; off += ilen) { uint64_t ip = start + off; printed += ip__fprintf_sym(ip, thread, x.cpumode, x.cpu, &lastsym, attr, fp); @@ -1065,6 +1065,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, printed += print_srccode(thread, x.cpumode, ip); break; } else { + ilen = 0; printed += fprintf(fp, "\t%016" PRIx64 "\t%s\n", ip, dump_insn(&x, ip, buffer + off, len - off, &ilen)); if (ilen == 0) @@ -1074,6 +1075,8 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, insn++; } } + if (off != (unsigned)len) + printed += fprintf(fp, "\tmismatch of LBR data and executable\n"); } /* @@ -1114,6 +1117,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, goto out; } for (off = 0; off <= end - start; off += ilen) { + ilen = 0; printed += fprintf(fp, "\t%016" PRIx64 "\t%s\n", start + off, dump_insn(&x, start + off, buffer + off, len - off, &ilen)); if (ilen == 0) -- 2.20.1